Cap-crown slitter.



E. D. GILBERT.

CAP GROWN SLITTER.

APPLICATION FILED 001. 2, 1911.

1,058,743. Patented Apr. 15, 1913.

A TTORNE Y COLUMBIA PLANOGIIAPH C0..WASHINGTON, D4 c.

UNITED STATES PATENT OFFICE.

EDMUND ID. GILBERT, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA, PENNSYLVANIA,

A CORPORATION OF PENNSYLVANIA.

GAP-GROWN SLI'ITER.

Patented Apr. 15, 1913.

Serial No. 652,325.

To all whom it may concern: I

Be it known that I, EDMUND" D. GILBERT, a citizen of the United States, and a resident of Philadelphia, county of Philadelphia, State of Pennsylvania, have invented certain new and useful Imrovements in Gap- Crown Slitters, of which the following is a specification.

My invention relates to cap crown slitters which are employed by dentists for slitting cap crowns upon teeth or teeth roots to facilitate their removal therefrom in case removal becomes necessary.

Implements of the character to which my invention relates include bearing jaws or beaks adapted to bear upon the cusp surface of the cap crown and cutting or slitting jaws or beaks having cutting or slitting points which are adapted to cut or slit the side of such cap crown.

An implement of the character to which my invention relates and the manner or method of itsuse is illustrated and described in Letters Patent of the United States No. 553,718, granted January 28, 1896 to the assignee of Joseph B. Monfort. In the said patent the cutter or slitter is integral with the slitting jaw or beak and it has been found that in use the point, of the cutter or slitter is worn away and also that occasionally, through accident, such point is broken or chipped off. In either case, it is necessary to sharpen the cutter thus shortening the same and thereby to some extent destroying the calculated relations between the two beaks. The length of the cutter is thus means for adjustably and detachably con necting a slitting blade or member to' the cutting or slitting jaw thereof.

A further object is to provide such an implement with a. slitting blade or member which is. not only adjustable and detachable fjaw or beak 7 is of the claims without departing therefrom.

In the said drawing: Figure 1 is a view in side elevation of a cap crown slitter embodying my invent-ion; Fig. 2 is an edge view thereof lookin upwardly in Fig. 1; Fig. 3 is an enlarge side elevation of one end portion of the implement, the slitting jaw or beak being shown in longitudinal section and the slitting or cut-ting blade being shown in side elevation in proper position. with relation to the said jaw or beak; and Fig. 1 is a transverse section of the cutting jaw or beak on the line H of Fig. 1.

Upon. reference to the drawing it will be seen that the implement consists of two main or body members land 2 which cross each other near their forward ends and which are pivotally secured together at their point of crossing or intersection by a pivot 3. The said members are provided with forceps-like handles 4 and 5 and with a bearing jaw or beak 6 and a cutting or slitting jaw or beak 7.

The inner surface of the outer end of the bearing jaw or beak is concaved or curved ;as. indicated at 8 to form a recess for the purpose of providing a more secure bearing or better hold upon the cusp end of the cap crown to be removed than could be obtained if such recess were not present and if the inner side of the said outer end portion of the jaw were smooth or plain.

The outer side of the cutting or slitting provided with a slot 9 which extends longitudinally thereof and in" which a cutting or slitting blade 10 is secured. The said slot does not extend entirely through the jaw 7 so that a thin part 11 of the-inner portion thereof is left which covers and protects the inner edge of, the; l portion of the cutting blade 10. which does not project beyond the jaw or beak 7. The opposite side portions of the jaw 7 are provided with perforations 12 which are adapted to receive screws 13 employed for the purpose of securing and holding the blade 10 in the slot 9. There are two of the said perforations 12.

The central portion of the blade 10 is provided with three perforations 14: any two of which may be placed in alinement with the perforations 12 through the jaw 7 in order that the screws 13 may be passed through the alined perforations. Both ends of the cutting'blade 10 are provided with cutting points or edges as indicated at 15 and 16.

In operation the end of the jaw 6 is placed upon the coronal surface or cusp end of the metallic cap crown to be'removed, the said end being received in the said recess 8. The cutting end 15 is placed underneath the lower edge of the said cap crown and against the tooth or tooth root and then by compressing the handles 4 and 5 the said crown is easily slit or out from end to end.

As already pointed out, the cutting edges and points of a cutter or slitter are'worn away by use and occasionally are accidentally broken, necessitating sharpening. In the construction embodying my invention when the cutter or slitter, while occupying one position in the slot 9, has been shortened by sharpening so that it does not occupy a correct position with respect to the bearing jaw, the said cutting blade may be adjusted outwardly by removing the screws 13 and moving the blade forwardly. The screws are then replaced to secure the blade in its adjusted position in said slot 9. In case the cutting edge and point 15 becomes shortened to such an extent that it may not be used even after forward adjustment, the ends of the said blade may be reversed so as to bring the cutting edge and end 16 thereof into proper relative position with respect to the bearing jaw or beak 6. Such cutting point or end 16 may be used and adjusted exactly in the same way as has been described in connection with the cutting edge 15.

When the cutting blade is provided with three perforations, as indicated, it will be seen that provision is made for a single adjustment longitudinally of the blade for each end thereof. It will'be understood, however, that the number of perforations in the blade may be increased, within limits, and that the number of adjustments thereof may be correspondingly increased.

By reason of the fact that the slot 9 extends throughout the length of the jaw 7 the rear end of the knife, that is to say, the end thereof not in use, is concealed and protected, as is clearly shown in the drawings, not only protecting the hand or hands of a person handling the implement, but also protecting the portion of the blade itself which is not in use.

then both ends of the cutting blade have been used until they have worn too short to be satisfactory even after adjustment as described, the said blades may be discarded and a new blade substituted therefor.

It will be seen, therefore, that my invention provides not only for the adjustment of a blade in order to prolong the period during which a single blade may be used, but it also provides means whereby when a blade is worn out it may be discarded and a new blade substituted in lieu thereof thus enabling dentists to have on hand at all times an implement with a sharp slitting or cutting point without the necessity of purchasing from time to time an entirely new implement.

Having thus described my invention, I claim 1. A cap crown slitt-er comprising pivoted members having jaws one of which is for contact with the top of a cap crown and the other one of which is provided with a blade for slitting the cap crown at its side, which blade is adjustable lengthwise and is also detachable and reversible, and one side edge of each end portion of said blade being a cutting edge.

2. An implement of the character described, consisting of two members pivoted together intermediate their ends, the said members being provided with jaws, one of the said jaws being for contact with the top of a cap crown of a tooth and the other of said jaws having a slot in its outer edge which extends longitudinally thereof and also having a double-ended blade adjustably and detachably secured in said slot for slitting a cap crown at its side.

3. In an implement of the character described, the combination of two members, a pivot for pivotally connecting the said members at points intermediate their ends, the portions of the said members 11 3011 one side of the pivot constituting han les and the portions upon the opposite sides thereof constituting jaws, one of the said jaws being adapted for contact with the top of a cap crown and the other of said aws being provided with a seat formed therein and having holes extending therethrough across the said seat, a double-ended slitting blade located in the said seat, and having holes therethrough which may be placed successively in alinement with the holes in the said aw, whereby the said blade may be adjusted longitudinally, and means extending through the holes in the said jaw and in the said slitting blade for securing the latter in position.

4. A cap crown slitter comprising two members pivoted together and having jaws one of which is longer than the other, the

longer jaw being for contact With the top of In testimony that I claim the foregoing as a cap crown and the other shorter jaw being my invention, I have hereunto signed my 10 provided With a slot or groove in its outer name this 23rd day of September, A. D. edge and having a double-ended slitting 1911.

5 blade adjustably and reversibly secured in EDMUND D. GILBERT.

said slot or groove and both ends of which In the presence of blade are sharpened and constitute slitting GEORGE W. GABRIELL, ends for slitting a cap crown at its side. W. S. CUNNINGHAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatente,

Washington, D. G. 

